<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const gender = "boy";
      const birth = "2020-12-21";

      const MY_PI = "3.14";

      let str = "hello";
      str = "hello jack";
      // gender = "gril";
      // birth = "2020-12-23";
    </script>
  </body>
</html>
